////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary> Handles the prime chain of step 5. </summary>
///
/// <remarks> Darrell Plank, 5/27/2020. </remarks>
///
/// <param name="firstPrime"> The first prime to start the chain. </param>
////////////////////////////////////////////////////////////////////////////////////////////////////
private void HandlePrimeChain(GridLocation firstPrime)
{
var curPrimeLoc = firstPrime;
var curStarLoc = GetStarInColumn(curPrimeLoc.Col);
StarZero(curPrimeLoc);
while (!curStarLoc.IsNoLoc())
{
_rowStars[curStarLoc.Row] = -1;
curPrimeLoc = new GridLocation(curStarLoc.Row, _rowPrimes[curStarLoc.Row]);
curStarLoc = GetStarInColumn(curPrimeLoc.Col);
StarZero(curPrimeLoc);
}
}
internal static bool IsClear(GridLocation pos)
{
var x = pos.Col;
var y = pos.Row;
if (_mapClear[x] == null)
{
_mapClear[x] = new bool?[1000];
}
if (!_mapClear[x][y].HasValue)
{
var val = (ulong)(x * x + 3 * x + 2 * x * y + y + y * y + _favorite);
_mapClear[x][y] = (Bitops.BitCount(val) & 1) == 0;
}
return(_mapClear[x][y].Value);
}
private void StarZero(GridLocation loc)
{
// Step 2
_rowStars[loc.Row] = loc.Col;
}
internal Position(GridLocation location)
{
_location = location;
}